In general, private and government agencies-responsible for the supply of drinkable water, use mechanical measuring instruments to establish the bills they make to the consumers for the service rendered; as the performance of the meter is reduced when its components are worn, there are maintenance policies set in base to the total volume recorded, or the time elapsed since its installation.
The wearing of the measuring equipment is not only a function of the volume recorded and the quality of water; but particularly of the instant flow rates at which such volume goes through the meter. Efficiency is not only a function of the meter's accuracy, but of the proportion of volume that according to the characteristic consumption pattern of each consumer, is measured with the specific accuracy of the device at each instant flow rates of consumption.
Having a histogram of the instant flow rates of real consumption that a meter in service has been subject to, would allow to optimize the useful life of the devices in such way, that it is repaired or replaced at the most adequate and economic time for the water utility, taking into consideration both the relative income and investments; it would also be useful to ensure the right sizing and measuring technology.
On the other hand, an important element to consider in the supply of drinkable water, is the distribution of the demand throughout the day, as the infrastructure and operation are planned to be able to offer a good service in the peak hour of the day of peak demand. This has as a consequence the “sub-utilization” of the installed capacity during most of the year, and the need to increase such capacity, with the same criteria, at the slightest increase in population or demand.
It would be very useful for the water utility, to know the consumption volumes taking place during different periods of the day, so that besides providing elements for a better planning of the infrastructure and operation, it would allow to set different tariffs for different consumption times, as is the case of the telephone and electric power companies. That could introduce, via price, a modification of the demand that contributes to make the operation more efficient, and to take advantage of the existent infrastructure, even to the point of differing investments.
The case of the companies that render services supplying electrical power is well known, regarding that they have set programs of incentives and penalties to their greater consumers with the purpose of keeping their distribution networks with the optimal dimensions and not incur in unnecessary investments. The programs set have as an objective to distribute the demand, keeping a sound average of consumption during the day, and ensure that the power transported is consumed efficiently by the consumer.
Normally, the consumption of electrical power required for the distribution of water represents one of the major operative expenses of water utilities, and these are usually considered as great consumers. Then, it is necessary that water utilities control their consumption of electrical power, difficult task to set if the consumers have a completely different consumption behavior during the day to the one that is more convenient for the agency. To be able to charge for the service with tariffs based on time-of-use, would, therefore, help to link the consumption of water of the users to the times-of-use that are more convenient to utilities from the energy costs point of view.
Another element to consider, regarding the profitability of the water utilities, is the productivity and reliability of the methods employed to read the consumption of users with which the billing and collection processes start.
Several technologies of electronic reading have been developed up to date, which are available in the market, and offer great benefits; nevertheless, for many water utilities the cost-benefit relation of its implementation does not justify them yet.
There is currently a considerable number of devices that in the technical field referred to by the invention herein, carry out functions of electronic reading of the total volume consumed; nevertheless, they offer little additional information.
An electronic reading system that besides recording the total volume consumed, provides details of the instant flow rate and time-of-use would result on a very useful tool to obtain the aforementioned benefits.
On the other hand, there are equipments that allow the gathering of data for the sizing of distribution networks, obtaining (of) consumption profiles and selection of measuring equipment, nevertheless, these are used in selected points and zones and during short periods of time that may not even be representative, and besides their cost is very high.
To intend to apply these technologies to analyze the behavior of all consumers would require, besides huge investments, transmission channels with high bandwidth due to the big amount of data generated, or very long and non practical reading times.
One of the objectives of the present invention is to offer an electronic reading system for drinkable water tapping points that provides, besides the total volume consumed by the user, profiles of the instant flow rates of consumption and the periods of the day when this happens, through the use of a mechanical water meter equipped with pulse emitters.
Another objective of this invention is to provide such information in a compact way, so that it allows a quick and practical transmission, in a device that will have years of autonomy and that is adequate even for adverse installation conditions.
Another objective is to provide the water utilities with elements to make of their activity a more profitable one, through better informed programs for the maintenance of meters, a better use of the installed capacity, an efficient distribution of the supply throughout the day and even for differing investments.
Another objective of this invention, is to provide water utilities with information that allows them to estimate, from known errors inherent to the accuracy of mechanical meters at different instant flow rates, the volume of water that is currently considered as a physical loss, and even to compensate individual billing, inferring the supplied water not measured.
Another of the objectives of this invention is to provide water utilities operator with means that allows them to apply tariff schemes that are more creative, oriented to the efficient and sustainable use of drinkable water.
The System of this invention comprises a Micro-controller device that allows to modify the actions carried out, according to the requirements of the market or special needs of the operator.
The invention can be installed in a meter that provides the media and signals necessary for its interconnection, of which there are standards that many manufacturers have adopted.
The water flow is registered by the meter, which, each time it registers certain volume, emits a signal that is coupled to the circuitry of the System.
Each pulse emitted by the meter is sensed by the System of the present invention, and acts as a reference to measure the volume consumed and the difference of time between the occurrence of pulses is used to determine the flow rate. When each pulse occurs, the invention “wakes up” from a sleep state in which it normally is in to optimize the use of the power source and therefore extend its autonomy or useful life. For the present case, it is used, for example a Power Unit (BAT) (5) of lithium as source, as it will offer the system a useful life that can be higher than the one of the meter to which it has been interconnected.
The invention has a group of resident counters in a non-volatile memory. Within this group of counters, each represents the volume consumed within a flow rate range. When the invention determines the time elapsed between the last two pulses, it calculates the flow rate and will select within a range table which volume counter has to increase. With this, an “histogram” of frequency is obtained; this histogram shows the amount of volume that has been consumed within each preset interval of instant flow rate.
Concurrently, a real time clock which is an element contained in the present invention, is used to select among other group of counters, the one that corresponds to the period of the day when the pulse from the meter has been detected. With this, it is obtained a “histogram” of usage time which indicates the frequency of the volume consumed in the different time-of-use intervals assigned to each counter of the group, previously set.
As the meters may be installed on the street, for this case, the physical installation of the invention would be carried out in this same environment. Therefore, the invention provides the media to detect vandalism or fraud attempts intents and register them in its memory.
The information stored in the invention's memory, can be accessed through a serial communication medium (wired or wireless) and configured through these same media.